The John Hart hydroelectric facility is furthest downstream of the Strathcona-Ladore-John Hart cascading hydroelectric development on the Campbell River. It is located on Vancouver Island near the City of Campbell River approximately 6 km upstream from where the river enters the Strait of Georgia. The generating facilities require upgrades to meet current seismic guidelines, improve safety and reliability, improve efficiency of power production, and provide improved flow management to better meet environmental standards. Limnotek partnered with Hemmera Envirochem Ltd. in 2010 to complete analyses of potential impact to aquatic processes in John Hart Reservoir and the downstream Campbell River. A description of existing conditions included measurement of fish population size using hydroacoustics, sediment resuspension processes using in situ sampling and underwater video, trophic state, phytoplankton biomass and composition, water chemistry, and other attributes. Results were combined with evidence from the scientific literature to examine potential change to water quality and fish populations as a result of the development. To support regulatory review, Limnotek and Hemmera worked with the client to explain the ecological processes in easily understandable terms including identification of key issues, identifying the valued ecosystem components (VEC’s), showing interactions between project activities and the VEC’s, assessment of effects during and after construction, mitigation, and residual effects.